1. Field of the Invention
The invention relates generally to a method of treating depression in human beings. More particularly, the present invention relates to a method of temporarily alleviating the symptoms of depression in humans being while minimizing side effects such as hypertension.
2. Background of the Prior Art
Inhibition of the enzyme monoamine oxidase is associated with compounds having usefulness in the treatment of clinical symptoms of depression. U.S. Pat. No. 2,997,422 discloses that the trans isomer of 2-phenylcyclopropylamine is a potent inhibitor of monoamine oxidase. However, the clinical usage of trans-2-phenylcyclopropylamine and other monoamine oxidase inhibitors has been markedly restricted in recent years because of potential side effects, e.g. hypertension thought to be associated with monoamine oxidase inhibition. These hypertensive and other side effects are thought to be caused by the action of toxic amines, such as tyramine, a toxic amine found in ripe cheese, which are not broken down in the body due to the inhibition of monoamine oxidase by the antidepressant compounds.
It is also known that trans-2-phenylcyclopropylamine may be resolved into its (+) and (-) enantiomers, Kaiser et al, "2-Substituted Cyclopropylamines", Journal of Medicinal and Pharmaceutical Chemistry, 5, 1243 (1962). It has also been shown that there is a differential activity of the (+) and (-) enantiomers of trans-2-phenylcyclopropylamine in rat brain synaptosomes, Horn and Snyder, "Steric Requirements for Catecholamine Uptake by Rat Brain synaptosomes: Studies with Rigid Analogues of Amphetamine", Journal of Pharmacology and Experimental Therapeutics, Vol. 180, No. 3 (1972).